Unraveling the mechanisms of flavor improvement in salt-reduced dry fermented sausages: Insights from yeast-modulated microbial interactions.

The present study investigated the modulatory effects of Candida zeylanoides AKS6 and Debaryomyces hansenii AKS44 on the quality profile attributes of reduced-NaCl fermented sausages. Results indicated that yeast inoculation decreased pH, moisture content and water activity of reduced-NaCl fermented sausages, establishing a foundation for enhanced microbial safety. Microbiome analysis revealed that the inoculated strains dominated the fungal community, exerting competitive exclusion against endogenous undesirable fungi (e.g., Trichosporon), while synergistically promoting beneficial lactic acid bacteria such as Latilactobacillus and Weissella. Volatile profiling demonstrated that NaCl reduction induced severe flavor defects. Yeast inoculation reduced formic acid content and mitigated lipid oxidation. Furthermore, driven by enhanced microbial esterification, the synthesis of fruity esters was promoted. This microbial restructuring drove the flavor improvement: suppression of off-flavor fungi combined with lactic acid bacteria-mediated ester biosynthesis enriching the fruity ester profile. Specifically, the odor activity value of methyl hexanoate significantly increased, becoming the dominant aroma contributor. These findings highlight the remarkable potential of C. zeylanoides AKS6 and D. hansenii AKS44 as starter cultures to reconstruct the microbial metabolic network and rescue the flavor quality of low-sodium fermented meat products.